Featured Research

from universities, journals, and other organizations

Study reveals flu-fighting role for well-known immune component

Date:
June 26, 2012
Source:
University of Georgia
Summary:
Scientists have discovered a new flu-fighting role for a well-known component of the immune system. The researchers found that administering a cell-signaling protein known as IL-15 to mice infected with influenza reduces their peak viral load by nearly three times.

University of Georgia scientists have discovered a new flu-fighting role for a well-known component of the immune system. Kimberly Klonowski, assistant professor of cellular biology in the UGA Franklin College of Arts and Sciences, and her colleagues found that administering a cell-signaling protein known as IL-15 to mice infected with influenza reduces their peak viral load by nearly three times.

"We gave the IL-15 intranasally and found that it enhanced the movement of the immune system's natural killer cells and CD8 T cells into the lung airways," said Klonowski, whose findings were recently published in the journal PLoS ONE. "As a result, the animals that received it cleared the virus faster than the control group."

Klonowski cautioned that the protein is only effective against influenza for a defined period of time immediately following infection, which would make its use as a flu treatment difficult to implement. She added that IL-15 has been tested as a vaccine-booster, or adjuvant, in other viral diseases such as HIV, monkey pox and hepatitis B; understanding its mechanism of action is essential to maximizing its effectiveness in these contexts.

IL-15 was discovered nearly 20 years ago and is part of a group of immune system proteins known as interleukins. Klonowski noted until recently, however, its primary role was thought to be the maintenance of immune memory cells. Yet Klonowski and her colleagues found that concentrations of the protein surge in the respiratory tract in response to influenza infections, which led them to hypothesize that it also might play a role in controlling the virus.

The scientists devised a series of experiments in mice to discern the role of IL-15 in the immune response. It turns out that IL-15 is one of the body's critical first responders during influenza infection.

First, the scientists blocked the action of IL-15 in mice infected with influenza and found that the number of natural killer cells was reduced 20-fold at the site of infection in comparison with the control group, which received a placebo. Next, scientists administered IL-15 into the airways of mice infected with influenza and found that these mice had three times more natural killer cells than the control group. In addition, their peak viral load decreased by nearly three times.

Klonowski said that despite what their name might suggest, natural killer cells really aren't the most effective components of the immune system. They do indeed kill infected cells, but not in numbers great enough to completely eradicate infection. CD8 T cells that arrive later in the immune response are the ones that clear the infection, riding in like a cavalry to save the day. Klonowski's study suggests that CD8 T cells require the initial presence of natural killer cells, which send some still-unknown signal that subsequently attracts CD8 T cells to the infection site. Her study found that without the presence of IL-15 and the natural killer cells it recruits, the cavalry never makes it to the site of the battle in the respiratory tract.

The researchers are now working to identify the molecular signals that the natural killer cells send with the ultimate goal of directing CD8 T cells more rapidly and precisely to the site of infection. "Even though this paper deals with natural killer cells, we are still really focused on the CD8 T cells, because they're the cell population that is required for complete viral clearance," she said.

The research was supported by the National Institutes of Health under award numbers AI077038 and AI081800.


Story Source:

The above story is based on materials provided by University of Georgia. The original article was written by Sam Fahmy. Note: Materials may be edited for content and length.


Journal Reference:

  1. Katherine C. Verbist, David L. Rose, Charles J. Cole, Mary B. Field, Kimberly D. Klonowski. IL-15 Participates in the Respiratory Innate Immune Response to Influenza Virus Infection. PLoS ONE, 2012; 7 (5): e37539 DOI: 10.1371/journal.pone.0037539

Cite This Page:

University of Georgia. "Study reveals flu-fighting role for well-known immune component." ScienceDaily. ScienceDaily, 26 June 2012. <www.sciencedaily.com/releases/2012/06/120626114952.htm>.
University of Georgia. (2012, June 26). Study reveals flu-fighting role for well-known immune component. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2012/06/120626114952.htm
University of Georgia. "Study reveals flu-fighting role for well-known immune component." ScienceDaily. www.sciencedaily.com/releases/2012/06/120626114952.htm (accessed September 1, 2014).

Share This




More Health & Medicine News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Liberia Continues Fight Against Ebola

Liberia Continues Fight Against Ebola

AFP (Aug. 30, 2014) Authorities in Liberia try to stem the spread of the Ebola epidemic by raising awareness and setting up sanitation units for people to wash their hands. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
California Passes 'yes-Means-Yes' Campus Sexual Assault Bill

California Passes 'yes-Means-Yes' Campus Sexual Assault Bill

Reuters - US Online Video (Aug. 30, 2014) California lawmakers pass a bill requiring universities to adopt "affirmative consent" language in their definitions of consensual sex, part of a nationwide drive to curb sexual assault on campuses. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
New Drug Could Reduce Cardiovascular Deaths

New Drug Could Reduce Cardiovascular Deaths

Newsy (Aug. 30, 2014) The new drug from Novartis could reduce cardiovascular deaths by 20 percent compared to other similar drugs. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins